1. Field of the Invention
This invention belongs to the field of pharmaceutical chemistry, and provides a convenient process for the synthesis of certain thiazoles which are intermediates for the preparation of valuable anti-ulcer drugs.
2. State of the Art
Thiazoles have been prepared before by processes having a relationship to the present process. For example, Hooper and Johnson, working with barbituric acids in 1934, prepared a 2-methylthiazole by the reaction of 1,3-dichloropropanone and thioacetamide. J. Am. Chem. Soc. 56, 470-71 (1934). Brown and Dubarry, Tet. Let. 2797-98 (1969), made 4-chloromethyl-4-hydroxy-2-phenyl-2-thiazoline by reaction of thiobenzamide and 1,3-dichloropropane. Other reports in the literature show rather similar reactions to prepare 4-chloromethylthiazoles and 2-thiazolines. The usual conditions, however, reaction in an acid mixture, or in the presence of a strong base such as pyridine, are not effective to form the presently desired product, apparently because of the substituted aminomethyl group at the 2-position of those desired products.